The mechanism of egg production improvement in laying hens before and after molting revealed by transcriptome and metabolome integration

The objective of this research was to examine the effects and underlying mechanisms of forced molting on the laying rate of hens. A total of ninety 500-day-old laying hens were randomly assigned to three groups: a control group (CK), a starvation group (SG), and a recovery group (RG). The study evaluated follicular development in hens and measured the expression levels of antioxidant, lipid, and inflammatory factors in their serum. Additionally, transcriptomic and metabolomic analyses were performed to assess the effects of forced molting on gene expression and metabolic profiles in hens. The findings indicated that forced molting led to an increase of laying rates, a reduction in follicular closure, and a significant rise in the levels of antioxidant enzymes such as GSH, CAT, and SOD, alongside a decrease in MDA levels. Furthermore, there were significant reductions in the blood lipid levels of LDL, HDL, TC, and TG. Additionally, there were notable differences in the inflammatory markers TNF-α, IL-1, and IL-6. The transcriptomic and metabolomic data revealed that forced molting influenced the activation of the PI3K-AKT and mTOR signaling pathways, affecting fatty acid metabolism in laying hens and modulating the expression of associated genes. In conclusion, this study demonstrates that forced molting is an effective strategy for enhancing the laying rate of hens. Furthermore, it provides a valuable theoretical framework for advancing breeding practices aimed at improving egg production.